Water-tube boiler



Jan. 18,1927.

w. HoPF WATER TUBE BOILER Filed Sept. 25, 1925 Patented a... 18, 1927.

UNITED STATES- PATENT OFFICE.

WILHELlI norr, or xlnL, GERMANY. ASSIGNOR TO FRIED. xaurr onmunmwnnr'r AKTIENQESEIJLSCHAFT, or KIEL-GAARDEN, GERMANY.

WATER-TUBE BOILER.

application flled sep tember 25, 1925, Serial No. 58,670, and in Germany Januar 2.1925.

In water tube boilers consistingof one or more upper andlower drums and nests of tubes connecting the same, the guiding of the hot gases is mostly performed by uniting a some rows of tubes into agas-tight tube-- .wall. In this respect, tube-walls lying at the outer walls'of the boiler mainly serve the purpose of restricting to the lowest possible degree the loss of heat to the outside.

The invention relates to'water tube boilers of the kind stated and has more particular reference to a construction in which a superheater is inserted in the first nest of tubes in such a manner "that a superheater tube each alternates with a row of water tubes'lying transverselyot the boilerdrums. In order toallow of the superheater to be inserted in this manner, one has-hitherto omitted the corresponding tubes of the tube-wall at the places where the' super-heater tubes pass through the outer tight tube-wali into the .nest of water tubes. However, the tightwallis thereby interrupted at those places on the entire height of the boiler so that the loss of heat to the' outside is considerably increased. I

4 The invention has for its object to avoid this drawback. This is attained according to the invention by bending at the places 7 where the superheater tubes penetrate into the nest of tubes, the corresponding tubes of theouter tight tube-wall for such a length behind the neighbouring tubes that openings are produced through which the superheater tubes can be introduced into the nest of water'tubes.

Two embodiments of v the subject-matter of the invention are illustrated in the accom'panying drawing in which:

Fig. lisa section, transverse of the drum axis, through .a boiler constructed in accordance with the invention,

Fig.2 is a similar section of a boiler provided with another form of superheater,

Fig. 3 is 'a view' of the front tight tube wall corresponding to Fig. 1,

Fig. 4 is'a section through the tight tubewall along the'line 4L4 of Fig. 3, I

' Fig. 5 is a section through the tube-wall in the range of the superheater along the line 5 5 of Fig. 3.

The embodiment according to Fig. 1 will be'described first. I -lhe upper drum A is connected with the lower drum B by a nest of water tubes C.

The outer rows of tubes 0, 0 are arranged close together for the purpose oi forming" gas-tight tube-walls. The path of the gases of combustion is indicated by an an ow. Arranged in the nest of tubes is a superheater 1) consisting of zig-zag tubes which open into collectors (1 outside the boiler. A pipe 15 connects the super-heater with the steam space ofthe upper drum A. The superheater is arranged so that a superheater tube each alternates with a row of water tubes lying transversely of the boiler-drums. At

the places where the superheating tubes penetrate into the nest of water tubes, the corresponding water tubes 0 of the outer tig t tube-wall c 0 are'bent behind the adjacent tubes'c (Figs. 1, 3 and 5) in such a manner that openings are produced through which the superheater tubes can be inserted into the nest of water tubes, while 76 the tube-wall is tightly closed above and below those places. I

In the arrangement according-to Fig.2 the super-heater D consists of several Ushaped tubes which are connected to collectors d 80 andbent so that they extend upwardly into the nest of water tubes. In this case, the superheater tubes are passed through the tight tube-wall rather close to. the lower drum 13 Therefore the bent-off pipes c are not bent back into the plane of the tight wall below the superheater but they are v uided down in their'bent-ofi position and astened in the lower drum.

Claims: Y 1., A water tube boiler comprising an upper and a lower drum, a nest of water tubes connecting said drums with each other, said nest including inner tube and anouter tubewall consisting of tubes in close contact along a portion of their length for guiding the heating gases, some of'the tubes of the tube-wall being bent back behind adjacent tubes of the tube-wall to form openings in said tube-walli and a. superhedter comprlsing tubes inserte through said openings and extending between the inner tubes of said nest.

2. A water tube boiler of the kind set forth in claim 1, in which the tubes of the.

superheater penetrate the outer tube-wall in proximity to the lower drum and in which the bent-back tubes of the said wall are ex- 10 tended down to the lower drum in their bentba'ck position.

The foregoing specification signed at Hamburg, Germany, this 29th day of August, 1925.

WILHELM HOPF. 

